C++ Sort Function: Guide with Examples

In C++, the sort function is used to sort elements in a container, either in default ascending order or according to a custom sorting rule.

Here is a basic example of sorting integer elements in a vector container.

#include <iostream>
#include <vector>
#include <algorithm>

int main() {
    std::vector<int> numbers = {4, 2, 1, 5, 3};
    
    // 使用sort函数对容器中的元素进行排序
    std::sort(numbers.begin(), numbers.end());
    
    // 打印排序后的结果
    for (int num : numbers) {
        std::cout << num << " ";
    }
    
    return 0;
}

If you want to sort in descending order, you can use greater() as the third parameter passed to the sort function.

std::sort(numbers.begin(), numbers.end(), std::greater<int>());

If you want to customize the sorting rules, you can use a lambda expression as the third parameter passed to the sort function, for example sorting by the absolute value of numbers.

std::sort(numbers.begin(), numbers.end(), [](int a, int b) {
    return abs(a) < abs(b);
});

This allows for sorting the elements in the container based on a custom sorting rule.